Knee replacement joints created by 3D printer for first time in breakthrough by US university

Knee replacement joints created by 3D printer for first time in breakthrough by US university

Printable synthetic cartilage which can be perfectly shaped to fit a knee joint has been designed by scientists in the US.

Duke University in North Carolina said the breakthrough will allow surgeons to 3D print replacement parts which are an exact match for a patient’s anatomy.Human knees come with a pair of built-in shock absorbers called menisci, ear-shaped pods of cartilage, which are nestled between the thigh and shin bones, and which cushion each step.

But a lifetime of wear-and-tear can permanently damage the joints, leading to pain and an increased risk of developing arthritis.

The new hydrogel-based cartilage is the first to match human cartilage in strength and elasticity while also remaining 3-D-printable and stable inside the body.

“We’ve made it very easy now for anyone to print something that is pretty close in its mechanical properties to cartilage, in a relatively simple and inexpensive process,” said Dr Benjamin Wiley, an associate professor of chemistry at Duke.

“Shape is a huge deal for the meniscus. This thing is under a lot of pressure, and if it doesn’t fit you perfectly it could potentially slide out, or be debilitating or painful.”

Current implants either do not match the strength and elasticity of the original cartilage, or are not biocompatible, meaning they do not support the growth of cells to encourage healing around the site.

“The current gels that are available are really not as strong as human tissues, and generally, when they come out of a printer nozzle they don’t stay put — they will run all over the place, because they are mostly water,” added Dr Wiley.

Feichen Yang, a graduate student in Wiley’s lab came up with the new synthetic cartilage by mixing two types of hydrogel together with a special type of clay which allows it to be printed.

The research was published in the journal ACS Biomaterials Science and Engineering.